High-low speed attachment for drill presses



June 28, 1949. v r-. K. sTElN HIGH-LW SPEED ATTACHMEN'I: FOR DRILLPRESSES Filed Jan. 7, 1948 2 sheets-'sheet 1 ATI'DRNEYB June 28, 1949.F. K. sTElN 2,474,500

v HIGH-LOW SPEED ATTACHMENT FOR DRILL PRESSES Filed Jan. '7, 1948l 2sheets-shea 2 40 4Z 1 I) l f la g 54 45 a7 v f 37 53 l 35 "55 l @HT f 36I SZ IN VEN TOR.

Patented June 28, 1949 HIGH-LOW SPEED ATTACHMENT vFOR DRILL PRESSESFrederick Kenneth Stein, Rockford, Ill.

Application January 7, 1948, Serial No. 1,023

Claims.

The present invention relates to a high and low speed power transmissionattachment for drill presses and other machine tools, and moreparticularly to a power transmission of the belt and pulley type.

The primary object of the invention is to provide a belt and pulleypower transmission for drill presses and other machine tools which willenable the operator to shift the transmission belts in a quick and easymanner.

Another object of the invention is to provide a high and low speed powertransmission attachment for drill presses and other machine tools whichcan be easily installed on drill presses of conventional design andconstruction without materially altering the structure and thearrangement of the drive and driven pulleys forming a part of said drillpress.

Another object of the invention is to provide a high and low speed powertransmission attachment for drill presses and other machine tools whichcan be easily and quickly installed or removed so that the machine toolcan be quickly and easily converted with ease and facility.

Another object of the invention is to provide a high and low speed powertransmission attachment for drill presses and other machine tools whichwill permit the use of a large number of drills or other cutting toolsof various diameters by reason of the wide range of different cuttingspeeds available.

Another object of the invention is to provide a high and low speed powertransmission attachment for drill presses and other machine tools whichis adapted to be removably received on the column of a conventionaldrill press or similar machine tool by sliding the attachment inposition thereover without disturbing the remaining parts of the drillpress or machine tool.

Another object cf the invention is to provide a high and low speed powertransmission unit for drill presses and other machine tools which iscapable of being used with the shiitable drill press or machine toolhead in any of its positions of vertical adjustment. Since the unit isslidably mounted on the drill press column or support, it will followthe various adjustments so that the drive belts will remain in thesamehorizontal plane.

Other objects and advantages of the invention' will become apparentduring the course of the following description of the accompanyingdrawings wherein:

Figure 1 is a fragmentary side elevational View of the upper portion ofa drill press including (Cl. i4-242.11)

2 the drill press head showing the manner in which the high and lowspeed power transmission unit is assembled thereon.

Figure 2 is a top elevational View showing the manner in which the highand low Speed power attachment is installed and the location of thevarious drive belts.

Figure 3 is a top elevational view of the high and low speed powertransmission unit detached from the drill press to illustrate variousdetails of construction.

Figure 4 is a bottom view of the high and low speed power transmissionunit showing the manner in which the control lever is rockably mountedon one of the pulley bearing supports.

Figure 5 is a side elevational view of the high and low speed powertransmission attachment removed from the drill press to show thearrangement of the stepped transmission pulleys, and

Figure 6 is a longitudinal cross sectional view of the high and lowspeed power transmission attachment showing the general shape inlongitudinal section and illustrating the longitudinal slot in one endthereof to facilitate adjustment of one of the transmission pulleys.

In the drawings, wherein for the purpose of illustrating the inventionand wherein like reference characters will be employed to designate likeparts throughout the same, the reference character 5 will generally beemployed to represent the column of a conventional drill press or othermachine tool of a similar character, the upper portion being shown forthe purpose of illustration while the lower portion (not shown) issupported on a bench by means of a suitable stand.

Adjustably mounted on the upper end of the column 5 is a drill presshead 6 which generally comprises a casting shaped to provide asemicylindrical portion 'I flanged as at 8 to receive and cooperate witha semi-cylindrical casting A9 likewise flanged as at I0. The iianges 8and I0 are adapted to be bolted together by means of bolts or machinescrews II to clamp the semicylindrical castings 1 and `il in tightengagement with the supporting column or post 5.

The drill press head also includes a cylindrical portion I4 havingbearings in the upper and lower portions thereof for supporting a drillspindle I5 on the lower end of which is positioned a quill I6 anda'drill chuck I'I. An operating handle I8 is aiXed to a control shaft I9having a rack and gear connection (not shown) to move the quill IStoward and away from the work.

Formed on the semi-cylindrical casting 9 is a pair of spaced apartprojections or bosses 26 having studs 2l for supporting a plate 22 towhich the base 23 of an electric motor 24 is securely attached bysuitable screws 25. The armature shaft 26 of the motor is provided witha stepped or cone drive pulley 21 having a plurality of pulley grooves28 of different diameters. Similarly, the drill spindle l5 is provided'with: a. stepped orl cone pulley 2'9 arranged in anr in verted positionwith its pulley grooves 30 located opposite the pulley grooves 28. Indrill presses*` and other machine tools of tl'le-.above=described rtype, an endless transmission belt is passed oven the pulleys 21 and 29to drivingly connect the motor 24 to the drill spindle l5, andbyfarranging'- the transmission belt in correspondingly, posi.- tionedgrooves 28 and 30 of the respective pulleys 21 and 29, four drive speedsmay be attained;

The invention comprises a high and low speed power transmissionfattachment` consisting of.. a cross arm casting 33 havingf a centralenlarged hub portion 34 and integrated radially vextending arms 35. Thehub,pvortion;34risyprovided'with-an opening 36 ofadiameter-equalfto thediameter of casting can be assembled on said' column with a snug slidingfitto:v permit-easy. angular adjust.;

mentor movementzthereofrabout .the axis of. column or post 5.-Reinforcingif ribsv 31 are formed on the underside of said castingandsaid ribs".y extend',from.the-.hub portion-34 to.' a point adjacentthe ends. of said:arms-35.

Oneof said arms 35.is provided with'an opening 38 for receiving aIpulley supporting spindle 39, upon which: is rotatably *mounted a4stepped cone -pulley' 49 having, aplurality of pulley grooves 4 I .ofidilerent diameters:l Suitable ybearing :wash-- ers 42and-43arerdisposed. between the arm 35. and stepped cone pulley 4D asWell as the upper portion of` the4` pulley, and l a retaining nut 44 toallowr free rotatiorrof saidpulley under driving. conditions; A`retaining.. nut 45. is-threaded: on therlowen` end offtheepulleyuspindle3.9, and said. retaining.A nut is= adapted-to lprovide 2a support for.'a contact lever 46.tohold the.1same in positionA on the, lower end ofsaidrpulley spindle 39. for a purpose whichwill.4V be hereinafter moretfully' described.v A-stop pin 41..is1-anchoredfin .van open ing in, saidcontrol lever andlisf positioned to: engagerthe arm 3.5` and limit.angular vdisplace-- mentof said lever Mounted onthe-other arm 35- of.the casting 1 33 isawpulleyspindle 48a for rotatably-v support-r ing asimilar steppedconez--pulley49;I having-L its stepped; pulley grooves501 arranged, inV reverse: order to the pulley grooves 4l of the pulley40:.: The opposite endsr'of.: therpulleyfspindle-48l are threaded, and Yone endzof said spindle -is .passed through an elongated slot-52inthezarm', andA has'.v threaded? thereon aI nutf Ai washer: 54 isinterposedv between thearmzandzinut; and".y the* Washer is offa diameterto-bridgeefthefsloti52 *and* securely hold -thegspind-le in position'.Thea' oppo= with .axretaining nut555-` and-Ta wa-Sher 56 isinter.; posedbetween the2nut55i=and pulley-bearing, to thereby yhold the pulleyin1position'forfree# rota'- tion', and' to' prevent aXial displacement*of tlie-v pulley;

The' pulleys 4l)`-and 49 are adaptedlto befdrivfingly-y connected` by*`means of an endlessT trans'-- mission belt 51; Whiclris l'received in'correspondspective pulleys 1495 and-i495` drills of'different diameters:

A coil spring 60 has one of its ends attached towa clip 6|, fastened tothe cylindrical portion I4Afof.. thedrilLpreSshead by means of a screw62; The opposite end'of the coil spring 60 is aixed to a screw eye 63,mounted in the control lever' 4611 and:v positioned intermediate theends thereof. When the control lever 46 is positioned as shown in Figure2, the casting 33 is yieldingly urged'iin:aicounter-clockwise directionto oppose the pull of the endless transmission belts 58 and 59, sothat'saidbelts Will be maintained in driving .relationshipwithcorresponding stepped pulley grooves. When the control lever 46 isturned in a counter-clockwise direction from therposi Jtion shown inFigure 2, to a positionA in which the drill press postor column 5, sothatv said.

the screw-eye 83 and coilA spring 6l) passes over the center of thepulley spindle 39, the yielding springaction will bereleased so that theendless transmission belts 58 and.` 59 can beeasily, re-

v,positioned with respect totheir. reversely related stepped pulleygrooves for changing the. drive speed ofthe drill spindle.l5.

When. it is desired, to change thev position of the drill press head 6,on the .column or support 35. 5, themachinescrews I l areloosened. topermit sliding, movementv of the head on the colunm. Asthis occursthehigh and low speed attachment 33 will follow the adjustment of thehead so that thehub v34.0f the. casting will besupported ,upon the upperend of. the, semi-.cylindrical portions. 1 and 9.. of the split castingsections.

ItY Willthus be understood, thatby releasing theyielding spring actionby manipulating, the control lever 46 Vas above described, ,thetransmisgpsionlbelts 58 and' 59 can be arranged withlrespect to. their.coplanar grooves. sov that the drill spindle l52may be driven atrelativelylow speeds orthe belts may be shifted to produce a relativelyhigh drill'spindle speed. Thus, the remquired cutting speed of the drillspindle canbe obtained for a large number of drills of differentdiameters for work pieces of ferrous and nonferrous metals.l Since theoperator may obtain the correct cutting speed by shifting the belts as gabove.described,. the drill press can be operated soV as'not'tov injurethe drill butv yet maintain maximum production.

Itis to be understoodthat the form of the invention herewith shown anddescribed is to. be

Goutaken as a preferred embodiment" thereof;4 and that'various changesin the shape, size. andarran-gement of partsmay be resorted to Withoutdeparting v,from the'spirit of Y'the invention or-the scope'of'thesubjoinedn claims;

j i Z sitehreadeei` endmffthe spindle-Asisprovided-e iD-f I cla m l. Ina drill vpress having a toolspindle and ai drive motor'supportedby'averticalcolumn, anY

arm supportedl by said` column; stepped cone pulleys mounted on"V eachend of`said arm withA O, the stepped grooves thereof arranged in'reverse' L relation; atransmission" belt' interchangeablypositioned"around said pulleys, aninterchangeable transmission belt'drivinglyconnecting the motor t A to one of said pulleys and an interchangeable1ng1ypositioned grooves' 41 and 56" ofl theare'- 75 l' transmission beltdrivinglyconnectingthe' other,

of isaidi pulleys'with tlietool spindle.

2. In a drill press having a tool spindle and a drive motor supported bya vertical column, an arm rockably mounted on said column to swinghorizontally, stepped cone pulleys mounted on each end of said arm withthe stepped grooves thereof in reverse relation, a transmission beltinterchangeably connecting said pulleys, an interchangeable transmissionbelt drivingly connecting the motor shaft with one of said pulleys, aninterchangeable transmission belt drivingly connecting the other of saidpulleys with the tool spindle and yielding spring means for urging saidarm in a direction to maintain the transmission belts in contactualengagement with their respective pulleys 3. In a drill press having atool head supported on a vertical column for mounting a drive motor anda tool spindle, a cross arm mounted on said column for free swinging andsliding movement, stepped cone pulleys rotatably supported on each endof said cross arm with their stepped grooves reversely arranged, steppedcone pulleys mounted on the armature shaft of said drive motor and toolspindle likewise having their stepped grooves reversely arranged, atransmission belt interchangeably and drivingly connecting the steppedcone pulleys on the cross arm, a transmission belt drivingly andinterchangeably connecting the stepped pulley on the drive motor withone of the stepped pulleys on the cross arm, a transmission beltdrivingly and interchangeably connecting the other of said steppedpulleys yon the cross arm with the stepped pulley on the drive spindle,and a spring connecting said cross arm to yieldingly urge said arm in adirection to maintain the transmission belts in tight driving engagementwith their respective stepped cone pulleys.

4. In a drill press having a tool head supported on a vertical columnand mounting a drive motor and a tool spindle, a cross arm mounted onsaid column for free swinging and sliding movement, stepped pulleysrotatably supported on each end of said cross arm with their steppedgrooves reversely arranged, a stepped cone pulley mounted on thearmature shaft of said drive motor, a stepped cone pulley mounted on thetool spindle, said last named stepped pulleys being arranged with theirstepped grooves in reverse order, an endless transmission belt drivinglyconnecting the stepped pulleys on the cross arm and adapted to beinterchangeably engaged with a pair of aligned pulley grooves thereof,an endless transmission belt drivingly connecting the stepped conepulley of the drive motor with one of the stepped cone pulleys on thecross arm, a transmission belt drivingly connecting the other of saidstepped cone pulleys on the cross arm with the stepped cone pulley onthe tool spindle, a coil spring having one end aixed to the drill presshead and its opposite end affixed to the cross arm to urge thetransmission belts in tight engagement with their respective pulleys andmeans for releasing the spring tension of said coil spring to allowinterchanging of said transmission belts and the positioning thereof inthe various grooves of the stepped pulleys.

5. In a drill press having a tool head supported on a vertical columnfor mounting a drive motor and tool spindle thereon, a cross arm mountedon said column to swing and slide freely thereon, stepped cone pulleysmounted on the ends of said arm and arranged with their grooves inreversely stepped order, a transmission belt drivingly connecting saidpulleys and adapted to be interchanged with the various pulley groovesthereof, a stepped cone pulley on the drive motor and tool spindle withtheir stepped pulley grooves likewise arranged in reverse order, atransmission'belt drivingly connecting the stepped cone pulley on thedrive motor with the stepped cone pulley on the cross arm which has itsstepped pulley grooves in reversely arranged order with respect to thegrooves on the drive motor, a transmission belt drivingly connecting theother of said stepped cone pulleys carried by said cross arm with thestepped cone pulley on the tool spindle, a lever pivotally mounted onone of the ends of said cross arm, a coil spring having one of its endsattached to the drill press head, and its opposite end to said lever anda stop pin mounted on said lever engageable with the cross arm to limitswinging movement thereof and maintain a yielding spring action on thecross arm in a counter-clockwise direction, said lever being adapted tobe shifted to release the tension of the coil spring and permitinterohanging of the transmission belts connecting the drive motor andthe tool spindle.

FREDERICK KENNETH STEIN.

No references cited.

